Overflow and return trap for vent pipes



Aug- 2 1 J. M. WIKMAN OVERFLOW AND RETURN TR AP FOR VENT PIPES Filed Aug. 25, 1950 Fig.

Fig. 2

IN V EN TOR.

Amnqs Patented Aug. 21, 1951 UNITED STATES OVERFLOW AND RETURN TRAP FOR VENT PIPES 2 Claims. 1

The present invention relates to liquid and gas separating devices and has more particular reference to a novel expansion and return trap for a vent pipe used, for example, on oil tankers and the like.

It-is a matter of common knowledge that turbulent activity and motion of oil in a full oil tank produces pressure pockets of air and gas which, in turn, act on the oil in such a way that it is forcibly surged through the vent pipe and gurgles and overflows from the exit of the pipe on the main deck. In an effort to overcome this problem, it has been found expedient and practicable to utilize a simple expansion trap which has both venting and draining facilities. It is, therefore, the purpose of the present invention to provide a simple and practical trap which may be located between a shelter deck and main deck which may be connected with the vent pipe and employed in such a manner as to allow for expansion, venting, trapping and return of the trapped oil product to the storage tank.

In carrying out the principles of the invention, the trap is fashioned from a length of pipe which is bent upon itself to provide several interconnected spaced parallel legs, the cross-section of each being greater than the cross-section of the vent pipe to which one or" the legs is communicatively connected.

More specifically, novelty is predicated on a :a

length of pipe which, with the use of upper and lower bends, defines the several legs, the upper end of one leg having a relativel small air and gas vent branch connected thereto and the lower junctional portions of the remaining legs being joined by a bend which defines a trap to which a return or drain pipe is connected.

Other objects and advantages will become more readily apparent from the following description and the accompanying sheet of drawings.

In the accompanying illustrative sheet of drawings, wherein like numerals are employed to designate like parts throughout the views:

Figure 1 is a fragmentary View of the main and shelter decks of a vessel showing the improved separator type overflow trap, its construction and mode of connection with the vent pipe; and

Figure 2 is an enlarged cross-section on the plane of the line 22 of Figure 1.

In Figure 1 of the drawings, the vent pipe, that is the common vent pipe, is denoted by the numeral 4 and this is communicatively connected with a, double bottom tank beneath the shelter deck. The shelter deck is denoted by the numeral 6 and the main deck above it by the numeral 8.

'unit which allows for expansion of oil and gases and air and which permits separation of the two is denoted generally by the numeral 12. It is a one-piece pipe construction and is characterized by three branches or legs denoted by the numerals I 6, l6 and it, respectively. These legs are all of cross-sections greater than the cross-section of the vent pipe 3. The upper end portion 29 of leg 18 is joined by a return bend 22 to the upper end of the leg it. The lower end portion of leg [6 is connected by a similar bend 215 to the corresponding end of leg it. These two legs id and It and the bend 2 A define a sort of overflow oil trap. This trap is connected by way of a return or drain 2% with a reduced neck 2% on the lower end of leg By the use of suitable threaded and flanged collars and coupling means, the collars 3d and the neck as is joined communicatively to the vent pipe and the respective pipes are attached to the deck t. The return pipe 28 is of a cross-section corresponding somewhat to that of the vent pipe. The auxiliary vent branch 34 also corresponds in cross-section with :l and 26 and the said auxiliary branch is joined to the upper end portion 36 of the leg Hi. This upper end portion is provided with a screw threaded neck 38 fastened in place by a retaining collar it on the deck, said neck carrying the aforementioned gooseneck Ill.

As previously stated, the objective is to substantially eliminate overflow and gurgling of oil above the main deck such as is caused by air pockets and pressure built up in the tank by the customary swish-swash of oil in a substantially full tank. When the overflow means 12 is installed between the two decks and with the branches or legs of suitable cross-section they coact in defining an appropriate overflow or expansion trap. Such oil under pressure as enters the leg i 3 may in the column provided thereby and the air and gases will pass out through the auxiliary vent "it into the upper end 36 of branch M and out through the discharge or goose-neck Q. The heavier oil portions will gravitate down through the branch or leg l6 and will be trapped at the elbow provided by the interconnected legs Id and i6, that is, at the point 24. The trapped oil will gravitate through the inclined return pipe 26 and flow back into the vent pipe 4.

It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after corisidering the description in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in the shape, size and arrangement of details coming within the field of invention claimed may be resorted to in actual practice, if desired.

Having described the invention, what is claimed as new isi 1. In a structure of the class shown and described, a vent pipe adapted for connection with an oil storage tank, an oil expansion, separating trap embodying a vertical leg connected at its lower end with said vent pipe, a second vertical leg opposed in parallelism to said first-named leg and an intervening vertical leg, the firstnamed leg being joined at its upper end to the upper end of said intervening leg and said latter leg being joined at its lower end to the corresponding lower end of said second-named leg,

ing trap and return device of the class shown and described comprising a vertically disposed leg adapted for connection at its intake end with the discharge end of a vent pipe, a second leg opposed to the first-named leg and a third leg interven ing between the first and second-named legs, a return bend connecting the upper end of the first-named leg with the corresponding end of the third leg, 9, return bend connecting the lower end of the second-named leg with the corresponding end of the third leg, a return pipe connected with said last-named bend and intake end of said first-named leg, and a vent pipe connected with the first-named bend and the upper end of said second-named leg? JOHN M.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,032,170 Wolff July 9, 1912 1,499,461 Kruppa July 1, 1924 2,241,655 Carlson May 13, 1941 

